[Runtime] Refactored Lookup/Construct to take function by ref

We don't need to copy the std::function because we don't modify it's
state.

Bug: v8:8015
Change-Id: I5320f78683fb7c1cca44b73e54312b3cc07b28cd
Reviewed-on: https://chromium-review.googlesource.com/1209782Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Florian Sattler <sattlerf@google.com>
Cr-Commit-Position: refs/heads/master@{#55708}

src/runtime/runtime-regexp.cc

@@ -38,7 +38,7 @@ uint32_t GetArgcForReplaceCallable(uint32_t num_captures,
 
 // Looks up the capture of the given name. Returns the (1-based) numbered
 // capture index or -1 on failure.
-int LookupNamedCapture(std::function<bool(String*)> name_matches,
+int LookupNamedCapture(const std::function<bool(String*)>& name_matches,
                        FixedArray* capture_name_map) {
   // TODO(jgruber): Sort capture_name_map and do binary search via
   // internalized strings.
@@ -1097,7 +1097,7 @@ class VectorBackedMatch : public String::Match {
 // RegExpBuiltinsAssembler::ConstructNewResultFromMatchInfo).
 Handle<JSObject> ConstructNamedCaptureGroupsObject(
     Isolate* isolate, Handle<FixedArray> capture_map,
-    std::function<Object*(int)> f_get_capture) {
+    const std::function<Object*(int)>& f_get_capture) {
   Handle<JSObject> groups = isolate->factory()->NewJSObjectWithNullProto();
 
   const int capture_count = capture_map->length() >> 1;